The long-term objective of this project is the prevention of adulthood transsexualism, adult transvestism, sexual orientation disturbance, and other adult sexual maladjustment by the procedures of early identification and therapeutic intervention. The primary objective of this grant is to identify existing psychological measures and to develop new behavioral and preference measures to evaluate gender and psychosexual adjustment in youth aged ten to eighteen years which could then be (a) applied in follow-up studies of previously referred young children (aged 4-10 years at first contact) evaluated for gender disturbance as they reach chronological ages above ten years, and (b) used in new efforts to develop scientifically-sound procedures for identifying gender disturbances in children over ten years of age who would be subsequently treated, using intrasubject designs. A secondary objective is to replicate and extend earlier treatment research on younger gender-disturbed children and children with other sexual adjustment problems. The new treatment studies for the target population of gender disturbed adolescents employ ABA reversal and multiple baseline intra-subject research designs to evaluate the behavioral treatment procedures of self-observation, self-reinforcement, external reinforcement of competing behaviors and other behavioral treatment intervention.